1. Field of the Invention
The presently claimed invention generally relates to a Printed Circuit Board (PCB) used for various electronic devices. More particularly, the presently claimed invention relates to a contact terminal provided on a PCB to contact various additional devices to the PCB.
2. Description of the Related Art
Generally, a contact terminal is a connection structure used for connection between devices or circuit devices, and is utilized in devices having various electronic circuits embedded therein. An example of such a structure being an interior wiring terminal box in a building, an electronic product like a vacuum cleaner, etc., a table clock, a portable media player, a battery connection structure of a wireless mouse, etc., a built-in antenna or a battery connection structure of a portable terminal, and so forth. The contact terminal is typically made using a leaf spring because the leaf spring can provide sufficient contact area and self elasticity for maintaining close contact with a counterpart component, such as a battery pack, etc., which is a contact target.
The contact terminal is bent into a ‘U’ shape, a first free end of the contact terminal is fixed to an inner side of an electronic device, such as a Printed Circuit Board (PCB). A second free end of the contact terminal is disposed to be spaced apart from the PCB. The first free end and the second free end of the contact terminal are connected to each other through a curved portion, such that the contact terminal has the ‘U’ shape. In a portable terminal, a counterpart component, such as a battery pack or an antenna device, is connected through the contact terminal, and in this case, the second free end contacts with the counterpart component.
FIGS. 1 and 2 show a terminal member 10 of a contact terminal and a structure in which the contact terminal is installed on a portable terminal 20 according to an embodiment of a conventional art.
Referring now to FIG. 1, the terminal member 10 is made by bending a leaf spring, in which a first free end 11 and a second free end 13 are positioned to face each other and are connected through a curved portion 19 in the form of a curved surface, thus forming an alphabetic ‘U’ shape. At an end portion of the second free end 13 is provided a contact surface 15 in the form of a curved surface a portion of which extends away from the first free end 11 and is bent toward the first free end 11. A part of the first free end 11 is bent in a similar manner as the contact surface 15 close to the contact surface 15 to prevent the second free end 13 from too far from the first free end 11.
FIG. 2 shows a cross-section of the portable terminal 20 in which a carrier 27 forming a built-in antenna device is installed inside an edge of a side of a housing 21. The carrier 27 may have an antenna pattern formed on an outer circumferential surface thereof and a speaker phone or a microphone embedded therein. On a back surface of the housing 21, a battery pack is removably provided and a separate cover member 23 for hiding and protecting the battery pack is also provided.
The terminal member 10 is positioned onto a PCB 25 disposed in the housing 21 to form the contact terminal. A part of the carrier 27 is positioned to face a part of the PCB 25, and the terminal member 10 is interposed between the carrier 27 and the PCB 25. The first free end 11 is fixed onto a surface of the PCB 25, and the second free end 13 is positioned to face a part of the carrier 27, such that the contact surface 15 contacts the carrier 27. A feeding line of an antenna pattern formed in the carrier 27 contacts the contact surface 15, thus being connected to a communication circuit provided on the PCB 25.
However, such a conventional contact terminal is difficult to apply to a portable terminal, especially since new versions of portable terminals continue become thinner than previous versions. In other words, in a built-in antenna connection structure, a part of a PCB and a part of a carrier face each other and a terminal member is disposed between the PCB and the carrier. Due to the height of the conventional terminal member, reduction of the thickness of the portable terminal is limited. The thickness may be gradually reduced toward the edge of the portable terminal, making a user feel that the portable terminal appears thinner than in actuality. However, in the terminal of this type shown in FIG. 2, it is difficult to secure a mounting space for a built-in antenna due to the structure of the contact terminal The space for installing the contact terminal may be secured by cutting a part of the carrier, but in this case, an area for forming the antenna pattern is reduced.